Field of the Invention
The present invention relates to a driving method for a photoelectric conversion apparatus, and it particularly relates to a driving method for a photoelectric conversion apparatus including a variable gain amplifier, a photoelectric conversion apparatus, and an imaging system.
Description of the Related Art
In the imaging apparatus field, a high S/N ratio and a wide dynamic range have been desirable. Japanese Patent Laid-Open No. 2005-175517 discloses a variable gain amplification unit provided in each column of a pixel array for an enlarged dynamic range with a higher S/N ratio kept. Japanese Patent Laid-Open No. 2005-175517 further discloses setting a gain of the amplification unit based on a result of detection of a signal level of an output signal from the amplification unit.
A configuration example of the amplification unit is further disclosed therein in which capacitative elements having different capacitance values from each other are provided in parallel in a feedback path of the amplifier (FIG. 14). The capacitative element to be electrically connected to the feedback path may be switched to switch the gain of the amplification unit.
Japanese Patent Laid-Open No. 2005-175517, however, does not disclose what kind of sequence is applied to switch the capacitative elements provided on the feedback path. The present inventor has found that some sequences for switching the connection of the capacitative elements provided in the feedback path may cause an offset error.